Misleading Policy Messages from the Period TFR: Should We Stop Using It?

Sobotka T & Lutz W(2009).Misleading Policy Messages from the Period TFR: Should We Stop Using It?
[[European Demographic Research Papers]] 4/2009, Vienna Institute of Demography of the Austrian Academy of Sciences, Vienna, Austria (2009)

Abstract

Public discussions about fertility trends and policies in developed countries refer almost exclusively to the period Total Fertility Rate (TFR), which is commonly misinterpreted as the "mean number of children per woman" as if it were a cohort measure of fertility. We argue that the use of this indicator frequently leads to incorrect interpretations of period fertility levels and trends, resulting in distorted policy conclusions and, potentially, in misguided policies. We illustrate this point with four policy-relevant examples, drawn from contemporary Europe. These illustrations show that the TFR (a) inflates the presumed gap between fertility intentions and realised fertility, (b) erroneously suggests a significant fertility increase in many countries of Europe after the year 2000, (c) often exaggerates the level of immigrants' fertility and (d) frequently suggests that family-related policies which led to shorter birth spacing in fact brought an upward swing in fertility level. We argue that there seems to be no policy-relevant question for which the period TFR would be the indicator of choice to be preferred over other existing measures, which range from measures related to future cohort size (total number of births) to sophisticated fertility indexes controlling for age, parity, duration since previous birth and tempo effect. Hence, there is a strong case for stopping the use of the period TFR as a one-fits-all fertility indicator which is now common practice.